So let's start with Marcion. When Tertullian in Book Three introduces the notion of Marcion calling 'Jesus' a phantasma he does so by saying that Marcion has previously borrowed from Jews, presumably Jewish writers, but is now speaking on his own authority. The first sentence of that chapter (chapter 8) reads:
Desinat nunc haereticus a Iudaeo, aspis quod aiunt a vipera, mutuari venenum, evomat iam hinc proprii ingenii virus, phantasma vindicans Christum. Nisi quod et ista sententia alios habebit auctores, praecoquos et abortivos quodammodo Marcionitas, quos apostolus Ioannes antichristos pronuntiavit, negantes Christum in carne venisse, et tamen non ut alterius dei ius constituerent, quia et de isto notati fuissent, sed quoniam incredibile praesumpserant deum carnem
Let the heretic now give up borrowing poison from the Jew,— the asp, as they say, from the viper: let him from now on belch forth the slime of his own particular devices, as he maintains that Christ was a phantasm: except that this opinion too will have had other inventors, those so to speak premature and abortive Marcionites whom the apostle John pronounced antichrists, who denied that Christ was come in the flesh,a yet not with the intention of setting up the law of a second god—else for this too they would have been censured <by the apostle>—but because they had assumed it incredible that God <should take to him human> flesh.
Our heretic must now cease to borrow poison from the Jew--"the asp," as the adage runs, "from the viper"117 --and henceforth vomit forth the virulence of his own disposition, as when he alleges Christ to be a phantom. Except, indeed, that this opinion of his will be sure to have others to maintain it in his precocious and somewhat abortive Marcionites, whom the Apostle John designated as antichrists, when they denied that Christ was come in the flesh; not that they did this with the view of establishing the right of the other god (for on this point also they had been branded by the same apostle), but because they had started with assuming the incredibility of an incarnate God.
The next lines:
Quo magis antichristus Marcion sibi eam rapuit praesumptionem, aptior scilicet ad renuendam corporalem substantiam Christi, qui ipsum deum eius nec auctorem carnis induxerat nec resuscitatorem, optimum videlicet et in isto, et diversissimum a mendaciis et fallaciis creatoris. Et ideo Christus eius, ne mentiretur, ne falleret, et hoc modo creatoris forsitan deputaretur, non erat quod videbatur, et quod erat mentiebatur, caro nec caro, homo nec homo, proinde deus Christus nec deus. [3] Cur enim non etiam dei phantasma portaverit? An credam ei de interiore substantia qui sit de exteriore frustratus? Quomodo verax habebitur in occulto tam fallax repertus in aperto? Quomodo autem in semetipso veritatem spiritus fallacia carnis confundens, negatam ab apostolo lucis, id est veritatis, et fallaciae, id est tenebrarum, commisit communicationem? [4] Iam nunc cum mendacium deprehenditur Christus1 caro, sequitur ut et omnia quae per carnem Christi gesta sunt mendacio gesta sint, congressus, contactus, convictus, ipsae quoque virtutes. Si enim tangendo aliquem liberavit a vitio vel tactus ab aliquo, quod corporaliter actum est non potest vere actum credi sine corporis ipsius veritate. Nihil solidum ab inani, nihil plenum a vacuo perfici licuit. Putativus habitus, putativus actus: imaginarius operator, imaginariae operae.
Now, the more firmly the antichrist Marcion had seized this assumption, the more prepared was he, of course, to reject the bodily substance of Christ, since he had introduced his very god to our notice as neither the author nor the restorer of the flesh; and for this very reason, to be sure, as pre-eminently good, and most remote from the deceits and fallacies of the Creator. His Christ, therefore, in order to avoid all such deceits and fallacies, and the imputation, if possible, of belonging to the Creator, was not what he appeared to be, and reigned himself to be what he was not--incarnate without being flesh, human without being man, and likewise a divine Christ without being God! But why should he not have propagated also the phantom of God? Can I believe him on the subject of the internal nature, who was all wrong touching the external substance? How will it be possible to believe him true on a mystery, when he has been found so false on a plain fact? How, moreover, when he confounds the truth of the spirit with the error of the flesh,118 could he combine within himself that communion of light and darkness, or truth and error, which the apostle says cannot co-exist?119 Since however, Christ's being flesh is now discovered to be a lie, it follows that all things which were done by the flesh of Christ were done untruly,120 --every act of intercourse,121 of contact, of eating or drinking,122 yea, His very miracles. If with a touch, or by being touched, He freed any one of a disease, whatever was done by any corporeal act cannot be believed to have been truly done in the absence of all reality in His body itself. Nothing substantial can be allowed to have been effected by an unsubstantial thing; nothing full by a vacuity. If the habit were putative, the action was putative; if the worker were imaginary the works were imaginary.
So Marcion, even more of an antichrist, seized upon this assumption, being better equipped in fact for denial of Christ's corporal substance, in that he had postulated that even Christ's god was neither the creator of flesh nor would raise it to life again—in this too supremely good, and entirely divergent from the lies and deceptions of the Creator. And that is why his Christ, so as not to tell lies, or to deceive, and in this fashion perhaps be accounted as belonging to the Creator, was not that which he appeared to be, and told lies about what he was—being flesh and not flesh, man and not man, and in consequence a Christ <who was> god and not god. For why should he not also have been clothed in a phantasm of god? Or can I believe what he says of his more recondite substance, when he has deceived me about that which was more evident? How shall he be accounted truthful about the secret thing, who has been found so deceptive about the obvious ? How can it have been that by confusing within himself truth of the spirit with deceit of the flesh, he conjoined that fellowship of light, which is truth, and deception, which is darkness, that the apostle says is impossible?b Also, now that it is found to be a lie that Christ <was made> flesh, it follows that all things that were done by means of Christ's flesh were done by a lie, his meetings with people, his touching of them, his partaking of food, his miracles besides. For if by touching someone, or being touched by someone, he gave freedom from sickness, the act performed by the body cannot be credited as truly performed apart from the verity of the body itself. It was not feasible for anything solid to be performed by that which is void, anything full by that which is empty. Putative constitution, putative activity: imaginary operator, imaginary operations.
Commentors on this section get sidetracked by Tertullian's line of reasoning here. The fact that Tertullian wants to make it 'dishonest' that Jesus/Man appeared as a phantasma doesn't mean it was so nor that Marcion and the Marcionites saw it that way. Indeed as Josephus provides us with a template for divine encounters where the divinity is a phantasma we can ignore pretty much all of Tertullian's hyperbole. So too what immediately follows:
[5] Sic nec passiones Christi eius fidem merebuntur. Nihil enim passus est qui non vere est passus; vere autem pati phantasma non potuit. Eversum est igitur totum dei opus. Totum Christiani nominis et pondus et fructus, mors Christi negatur, quam tam impresse apostolus demandat, utique veram, summum eam fundamentum evangelii constituens et salutis nostrae et praedicationis suae. Tradidi enim, inquit, vobis inprimis, quod Christus mortuus sit pro peccatis nostris, et quod sepultus sit, et quod resurrexerit tertia die. [6] Porro si caro eius negatur, quomodo mors eius asseveratur, quae propria carnis est passio, per mortem devertentis in terram de qua est sumpta, secundum legem sui auctoris? Negata vero morte, dum caro negatur, nec de resurrectione constabit. Eadem enim ratione non resurrexit qua mortuus non est, non habendo substantiam scilicet carnis, cuius sicut et mors, ita et resurrectio est. Proinde resurrectione Christi infirmata etiam nostra subversa est. Nec ea enim valebit, propter quam Christus venit, si Christi non valebit. [7] Nam sicut illi, qui dicebant resurrectionem mortuorum non esse, revincuntur ab apostolo ex resurrectione Christi, ita resurrectione Christi non consistente aufertur et mortuorum resurrectio. Atque ita inanis est et fides nostra, inanis est praedicatio apostolorum. Inveniuntur autem etiam falsi testes dei, quod testimonium dixerint quasi resuscitaverit Christum quem non resuscitavit. Et sumus adhuc in delictis. Et qui in Christo dormierunt, perierunt; sane resurrecturi, sed phantasmate forsitan, sicut et Christus.
On this principle, too, the sufferings of Christ will be found not to warrant faith in Him. For He suffered nothing who did not truly suffer; and a phantom could not truly suffer. God's entire work, therefore, is subverted. Christ's death, wherein lies the whole weight and fruit of the Christian name, is denied although the apostle asserts123 it so expressly124 as undoubtedly real, making it the very foundation of the gospel, of our salvation and of his own preaching.125 "I have delivered unto you before all things," says he, "how that Christ died for our sins, and that he was buried, and that He rose again the third day." [6] Besides, if His flesh is denied, how is His death to be asserted; for death is the proper suffering of the flesh, which returns through death back to the earth out of which it was taken, according to the law of its Maker? Now, if His death be denied, because of the denial of His flesh, there will be no certainty of His resurrection. For He rose not, for the very same reason that He died not, even because He possessed not the reality of the flesh, to which as death accrues, so does resurrection likewise. Similarly, if Christ's resurrection be nullified, ours also is destroyed. If Christ's resurrection be not realized,126 neither shall that be for which Christ came. [7] For just as they, who said that there is no resurrection of the dead, are refuted by the apostle from the resurrection of Christ, so, if the resurrection of Christ falls to the ground, the resurrection of the dead is also swept away.127 And so our faith is vain, and vain also is the preaching of the apostles. Moreover, they even show themselves to be false witnesses of God, because they testified that He raised up Christ, whom He did not raise. And we remain in our sins still.128 And those who have slept in Christ have perished; destined, forsooth,129 to rise again, but peradventure in a phantom state,130 just like Christ.
Thus also the sufferings of Marcion's Christ will fail to find credence: one who has not truly suffered, has not suffered at all, and a phantasm cannot have truly suffered. Consequently God's whole operation is overthrown. There is a denial of Christ's death, the whole weight and value of the Christian name, that death which the apostle so firmly insists on, because it is true, declaring it the chief foundation of the gospel, of our salvation, and of his own preaching. For I delivered unto you, he says, fast of all, that Christ died for our sins, and that he was buried, and that he rose again the third day.c But if his flesh is denied, how can his death be affirmed? For death is the particular experience of flesh, which by means of death is turned downwards into the earth from which it was taken: such is the law of its own Creator. But if the death is denied, as it is when the flesh is denied, neither can there be assurance of the resurrection. By whatever reasoning he did not die, by the same reasoning he did not rise again: which was that he had not the substance of flesh, to which death appertains, and likewise resurrection. But further, if doubt is cast upon Christ's resurrection, ours also is overthrown: for if Christ's is not valid, neither can that be valid for the sake of which Christ came. For just as those who said there was no resurrection of the dead are confuted by the apostle from the resurrection of Christ, so also, if Christ's resurrection fails, the resurrection of the dead is also taken away. And so also our faith is vain, and vain is the apostles' preaching.d They are also found false witnesses of God, because they have borne witness that he has raised up Christ, whom he has not raised up. And we are yet in our sins. And those who are fallen asleep in Christ, have perished—no doubt they will rise again, but in a phantasm perhaps, as Christ did.
All of this can be ignored because it doesn't tell us anything about what the Marcionites actually believed. The next lines do however and prove that they got their understanding of Jesus/Man as a phantasma from Greek Jewish sources like Josephus and Philo:
9. [1] In ista quaestione qui putaveris opponendos esse nobis angelos creatoris, quasi et illi in phantasmate, putativae utique carnis, egerint apud Abraham et Loth, et tamen vere sint et congressi et pasti et operati quod mandatum eis fuerat, primo non admitteris ad eius dei exempla quem destruis. Nam et quanto meliorem et perfectiorem deum inducis, tanto non competunt illi eius exempla quo nisi diversus in totum non erit omnino melior atque perfectior. [2] Dehinc scito nec illud concedi tibi, ut putativa fuerit in angelis caro, sed verae et solidae substantiae humanae. Si enim difficile non fuit illi putativae carnis veros et sensus et actus exhibere, multo facilius habuit veris et sensibus et actibus veram dedisse substantiam carnis, vel qua proprius auctor et artifex eius. [3] Tuus autem deus, eo quod carnem nullam omnino produxerit, merito fortasse phantasma eius intulerit cuius non valuerat veritatem. Meus autem deus, qui illam de limo sumptam in hac reformavit qualitate, nondum ex semine coniugali et tamen carnem, aeque potuit ex quacunque materia angelis quoque adstruxisse carnem, qui etiam mundum ex nihilo in tot ac talia corpora, et quidem verbo aedificavit. [4] Et utique, si deus tuus veram quandoque substantiam angelorum hominibus pollicetur, Erunt enim, inquit, sicut angeli, cur non et deus meus veram substantiam hominum angelis accommodarit undeunde1 sumptam? Quia nec tu mihi respondebis unde illa apud te angelica sumatur, sufficit mihi hoc definire quod deo congruit, veritatem scilicet eius rei quam tribus testibus sensibus obiecit, visui, tactui, auditui. [5] Difficilius deo mentiri quam carnis veritatem undeunde1 producere, licet non natae. Ceterum et aliis haereticis, definientibus carnem illam in angelis ex carne nasci debuisse si vere fuisset humana, certa ratione respondemus, qua et humana vere fuerit et innata: humana vere propter dei veritatem a mendacio et fallacia extranei, et quia non possent humanitus tractari ab hominibus nisi in substantia humana; innata autem, quia solus Christus in carnem ex carne nasci habebat, ut nativitatem nostram nativitate sua reformaret, atque ita etiam mortem nostram morte sua dissolveret resurgendo in carne in qua natus est ut et mori posset. [6] Ideoque et ipse cum angelis tunc apud Abraham in veritate quidem carnis apparuit, sed nondum natae quia nondum moriturae, sed et discentis2 iam inter homines conversari. Quo magis angeli, neque ad moriendum pro nobis dispositi, brevem carnis commeatum non debuerunt nascendo sumpsisse, quia nec moriendo deposituri eam fuerant; [7] sed undeunde1 sumptam et quoquo modo omnino dimissam, mentiti eam tamen non sunt. Si creator facit angelos spiritus et apparitores suos ignem flagrantem, tam vere spiritus quam et ignem, idem illos vere fecit et carnem, ut nunc recordemur et haereticis renuntiemus eius esse promissum homines in angelos reformandi quandoque qui angelos in homines formarit aliquando
[1] Now, in this discussion of yours,131 when you suppose that we are to be met with the case of the Creator's angels, as if they held intercourse with Abraham and Lot in a phantom state, that of merely putative flesh,132 and yet did truly converse, and eat, and work, as they had been commissioned to do, you will not, to begin with, be permitted to use as examples the acts of that God whom you are destroying. For by how much you make your god a better and more perfect being, by just so much will all examples be unsuitable to him of that God from whom he totally differs, and without which difference he would not be at all better or more perfect. [2] But then, secondly, you must know that it will not be conceded to you, that in the angels there was only a putative flesh, but one of a true and solid human substance. For if (on your terms) it was no difficulty to him to manifest true sensations and actions in a putative flesh, it was much more easy for him still to have assigned the true substance of flesh to these true sensations and actions, as the proper maker and former thereof. [3] But your god, perhaps on the ground of his having produced no flesh at all, was quite right in introducing the mere phantom of that of which he had been unable to produce the reality. My God, however, who formed that which He had taken out of the dust of the ground in the true quality of flesh, although not issuing as yet from conjugal seed, was equally able to apply to angels too a flesh of any material whatsoever, who built even the world out of nothing, into so many and so various bodies, and that at a word! [4] And, really, if your god promises to men some time or other the true nature of angels133 (for he says, "They shall be like the angels"), why should not my God also have fitted on to angels the true substance of men, from whatever source derived? For not even you will tell me, in reply, whence is obtained that angelic nature on your side; so that it is enough for me to define this as being fit and proper to God, even the verity of that thing which was objective to three senses--sight, touch, and hearing. [5] It is more difficult for God to practise deception134 than to produce real flesh from any material whatever, even without the means of birth. But for other heretics, also, who maintain that the flesh in the angels ought to have been born of flesh, if it had been really human, we have an answer on a sure principle, to the effect that it was truly human flesh, and yet not born. It was truly human, because of the truthfulness of God, who can neither lie nor deceive, and because (angelic beings) cannot be dealt with by men in a human way except in human substance: it was withal unborn, because none135 but Christ could become incarnate by being born of the flesh in order that by His own nativity He might regenerate136 our birth, and might further by His death also dissolve our death, by rising again in that flesh in which, that He might even die, He was born. [6] Therefore on that occasion He did Himself appear with the angels to Abraham in the verity of the flesh, which had not as yet undergone birth, because it was not yet going to die, although it was even now learning to hold intercourse amongst men. Still greater was the propriety in angels, who never received a dispensation to die for us, not having assumed even a brief experience137 of flesh by being born, because they were not destined to lay it down again by dying; [7] but, from whatever quarter they obtained it, and by what means soever they afterwards entirely divested themselves of it, they yet never pretended it to be unreal flesh. Since the Creator "maketh His angels spirits, and His ministers a flame of fire"--as truly spirits as also fire--so has He truly made them flesh likewise; wherefore we can now recall to our own minds, and remind the heretics also, that He has promised that He will one day form men into angels, who once formed angels into men.
9.1 If in this inquiry you think you can set against me the Creator's angels, alleging that they also, when in converse with Abraham and Lot,a were in a phantasm, evidently of putative flesh, and yet really met with them, and partook of food, and performed the task committed to them, <my answer will be> first, that you have no claim upon the evidences of that God whom you are concerned to depose. For, the more superior and the more perfect the character of the god you are commending, the more unbecoming to him are evidences belonging to that other: for unless he is entirely diverse from him he cannot be in any sense better or more perfect. Secondly, take note besides that we do not admit your claim that in those angels the flesh was putative: it was of veritable and complete human substance. For if it was not difficult for God to display true perceptions and activities in putative flesh, much easier did he find it to provide true perceptions and activities with true substance of flesh, the more so as he is himself
its particular creator and maker. Now your god, seeing that has never produced any flesh at all, may quite reasonably perhaps have brought in a phantasm of something he had not the ability to make the truth of. But my God, who reshaped into the quality we know, that flesh which he had taken up out of clay— it was not yet conceived of conjugal seed, yet was already flesh— was no less able out of any material whatsoever to construct flesh for angels as well: he had even built up the world out of nothing into all these various bodies, and had done this with a Word. And truly, if your god promises to men some time the true substance of angels—They will, he says, be as the angelsb—why should not my God too have granted to angels the true substance of men, from wheresoever he may have taken it? Since you for your part will not answer me when I ask from whence that angelic <substance> you speak of is <to be> taken, no more is required of me than to affirm as a fact, which is in keeping with God's dignity, the truth of that object which he presented to three witnesses, the senses of sight, and touch, and hearing. God finds it more difficult to tell lies than to bring into existence veritable flesh, from whatsoever source, even without the process of birth. There are yet other heretics, who state that if in the angels that flesh had been truly human it would have needed to pass through human birth: to these we give in answer a firm reason why it was both truly human yet exempt from birth. It was truly human for the sake of the truth of God, who is a stranger to all lying and deceit, and because <the angels> could not have been received by men on human terms if they had not been in human substance: yet it had not passed through birth because Christ alone had the right to become incarnate of human flesh, so that he might reform our nativity by his own nativity, and thus also loose the bands of our death by his own death, by rising again in that flesh in which he was born with intent to be able to die. For this reason he too on that occasion appeared along with the angels in Abraham's presence, in flesh veritable indeed though not yet born, because it was not yet to die, though it was even then learning to hold converse among men. Even more so the angels, who were never by God's intention to die for us, had no need to receive their brief experience of flesh by means of birth, because they were not intending to lay it down by means of death: yet from wheresoever it was they acquired it, and in whatsoever manner they finally disposed of it, they certainly did not tell lies about it. If the Creator maketh his angels spirits and his attendants a flaming fire,c no less truly spirits than truly fire, he is the same who also made them truly flesh, so that we may now set it on record, and report back to the heretics, that the promise of some time reforming men into angels is made by that <God> who of old time formed angels into men.
So in point of fact Marcion is continuing to borrow from the Jews throughout the section - from chapters 5, 6, 7, 8, 9 and 10.